Background: Inhaled nitric oxide (iNO) is a well-established treatment for neonatal hypoxic respiratory failure (HRF). However, iNO therapy initiation criteria have not been standardized. This report describes a follow-up survey administered to neonatologists who had completed an Awareness, Trial, and Usage Survey. The objectives were to compare stated target oxygenation index (OI) versus actual OI at which iNO is initiated in respondents' patients and identify factors associated with iNO initiation at other levels.
Methods: Neonatologists provided iNO-treated HRF patient data. Target and actual OI at initiation were determined. Patient groups were stratified by actual OI deviation from target [<4; at (±3); above: 4-10, 11-20, >20; not measured]. Reasons for above-target OI were determined.
Results: Of 83 invited neonatologists, 26 (31%) participated, providing data for 128 patients; 85/128 patients (66%) had OI measured at initiation with neonatologist-stated mean target OI 18.8±5.8. Actual mean OI was 26.2±10.3. iNO was initiated ≤ target in 30/85 patients (35%); most [55/85 (65%)] had iNO initiated when OI was above target. Patients aged ≤1 day and those receiving a fraction of inspired oxygen (FiO2) of 1.0 for more than 1 h had highest OIs at initiation.
Conclusions: Among surveyed neonatologists who treat infants with HRF with pulmonary hypertension (PH), there is a disparity between stated target versus actual OI for iNO initiation, particularly among infants <1 day old and those receiving FiO2 of 1.0 for more than 1 h. In term/near-term neonates with HRF with PH, neonatologists should consider implementing treatment protocols to ensure iNO initiation at stated target OI levels.